Java tutorial
/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.view.animation; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.res.TypedArray; import android.util.AttributeSet; /** * An animation that controls the position of an object. See the * {@link android.view.animation full package} description for details and * sample code. * */ public class TranslateAnimation extends Animation { private int mFromXType = ABSOLUTE; private int mToXType = ABSOLUTE; private int mFromYType = ABSOLUTE; private int mToYType = ABSOLUTE; /** @hide */ @UnsupportedAppUsage protected float mFromXValue = 0.0f; /** @hide */ @UnsupportedAppUsage protected float mToXValue = 0.0f; /** @hide */ @UnsupportedAppUsage protected float mFromYValue = 0.0f; /** @hide */ @UnsupportedAppUsage protected float mToYValue = 0.0f; /** @hide */ protected float mFromXDelta; /** @hide */ protected float mToXDelta; /** @hide */ protected float mFromYDelta; /** @hide */ protected float mToYDelta; /** * Constructor used when a TranslateAnimation is loaded from a resource. * * @param context Application context to use * @param attrs Attribute set from which to read values */ public TranslateAnimation(Context context, AttributeSet attrs) { super(context, attrs); TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.TranslateAnimation); Description d = Description .parseValue(a.peekValue(com.android.internal.R.styleable.TranslateAnimation_fromXDelta)); mFromXType = d.type; mFromXValue = d.value; d = Description.parseValue(a.peekValue(com.android.internal.R.styleable.TranslateAnimation_toXDelta)); mToXType = d.type; mToXValue = d.value; d = Description.parseValue(a.peekValue(com.android.internal.R.styleable.TranslateAnimation_fromYDelta)); mFromYType = d.type; mFromYValue = d.value; d = Description.parseValue(a.peekValue(com.android.internal.R.styleable.TranslateAnimation_toYDelta)); mToYType = d.type; mToYValue = d.value; a.recycle(); } /** * Constructor to use when building a TranslateAnimation from code * * @param fromXDelta Change in X coordinate to apply at the start of the * animation * @param toXDelta Change in X coordinate to apply at the end of the * animation * @param fromYDelta Change in Y coordinate to apply at the start of the * animation * @param toYDelta Change in Y coordinate to apply at the end of the * animation */ public TranslateAnimation(float fromXDelta, float toXDelta, float fromYDelta, float toYDelta) { mFromXValue = fromXDelta; mToXValue = toXDelta; mFromYValue = fromYDelta; mToYValue = toYDelta; mFromXType = ABSOLUTE; mToXType = ABSOLUTE; mFromYType = ABSOLUTE; mToYType = ABSOLUTE; } /** * Constructor to use when building a TranslateAnimation from code * * @param fromXType Specifies how fromXValue should be interpreted. One of * Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or * Animation.RELATIVE_TO_PARENT. * @param fromXValue Change in X coordinate to apply at the start of the * animation. This value can either be an absolute number if fromXType * is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise. * @param toXType Specifies how toXValue should be interpreted. One of * Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or * Animation.RELATIVE_TO_PARENT. * @param toXValue Change in X coordinate to apply at the end of the * animation. This value can either be an absolute number if toXType * is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise. * @param fromYType Specifies how fromYValue should be interpreted. One of * Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or * Animation.RELATIVE_TO_PARENT. * @param fromYValue Change in Y coordinate to apply at the start of the * animation. This value can either be an absolute number if fromYType * is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise. * @param toYType Specifies how toYValue should be interpreted. One of * Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or * Animation.RELATIVE_TO_PARENT. * @param toYValue Change in Y coordinate to apply at the end of the * animation. This value can either be an absolute number if toYType * is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise. */ public TranslateAnimation(int fromXType, float fromXValue, int toXType, float toXValue, int fromYType, float fromYValue, int toYType, float toYValue) { mFromXValue = fromXValue; mToXValue = toXValue; mFromYValue = fromYValue; mToYValue = toYValue; mFromXType = fromXType; mToXType = toXType; mFromYType = fromYType; mToYType = toYType; } @Override protected void applyTransformation(float interpolatedTime, Transformation t) { float dx = mFromXDelta; float dy = mFromYDelta; if (mFromXDelta != mToXDelta) { dx = mFromXDelta + ((mToXDelta - mFromXDelta) * interpolatedTime); } if (mFromYDelta != mToYDelta) { dy = mFromYDelta + ((mToYDelta - mFromYDelta) * interpolatedTime); } t.getMatrix().setTranslate(dx, dy); } @Override public void initialize(int width, int height, int parentWidth, int parentHeight) { super.initialize(width, height, parentWidth, parentHeight); mFromXDelta = resolveSize(mFromXType, mFromXValue, width, parentWidth); mToXDelta = resolveSize(mToXType, mToXValue, width, parentWidth); mFromYDelta = resolveSize(mFromYType, mFromYValue, height, parentHeight); mToYDelta = resolveSize(mToYType, mToYValue, height, parentHeight); } }